A multi-disciplinary research project at the University of Bath hopes to develop an efficient, portable and low cost continuous treatment system for contaminated drinking water for poor rural communities in developing countries.

The research team want to produce safe, clean drinking water for poor rural communities who don’t have access to a centralised water supply.

The researchers are using 3D printing to generate rapid prototypes and test them using a unique indoor solar light that can replicate pure sunlight in the lab. This testing will enable a better understanding of the optimal design of this household water treatment (HWT) system to most efficiently produce safe drinking water.

650 million people still without water

Despite the success of the Millennium Goal 7C - to halve by 2015 the proportion of the population without sustainable access to safe drinking water and basic sanitation - there are still 650 million people across the world without safe water. This project is leading the way in tackling one of the UN Sustainable goals ‘to ensure access to water and sanitation for all’.

Current water purification limitations

Existing methods for purifying water include boiling, chemical disinfection and filtration, all of which have numerous disadvantages. Currently, one of the simplest ways to treat microbial contained water is by using what is known as a “SODIS Bottle” (SOlar DISinfection), a simple plastic bottle which deactivates microbes through a combination of heat and UV light from the sun.

One limitation of the SODIS bottle is the lack of current knowledge of the time needed to decontaminate water which can depend on a number of factors. It is also a short term solution due to its limited durability.

Portable, sustainable and efficient

This project will build upon the principles of the SODIS bottle to design a simple, portable household water treatment (HWT) system capable of producing clean drinkable water sufficient for a small group of individuals.

The device will have no breakable parts, require no power source and will have greater durability than any other current HWT. The researchers predict that each device will be able to produce up to 35 litres of clean drinking water a day. The World Health Organisation (WHO) recommends each person needs 50 litres of water per day for basic sanitation (this includes personal hygiene, drinking water, sanitation and domestic use) but in most African rural communities, people only have access to up to 30 litres a day and as little as 5 litres in the most deprived areas.

Each device is envisaged to be made out of biodegradable plant-based plastic (PLA), weigh approximately 3KG and cost just £5 per unit with over 10,000 units being produced per year, ideally by locally trained workers.

These attributes will make it ideal for supplying water both in rural areas suffering from microbial contaminated water, as well as in crisis situations such as population movements due to war, and during times of natural disasters such as earthquakes and flooding.

Africa in focus

This project will concentrate on Africa as a key beneficiary of the technology. Africa has the lowest uptake of adequate HWT systems and 37 per cent of the world’s population that use an unimproved drinking source live in Sub-Saharan Africa. In particular, Malawi will be used as a case study to test the prototype devices in the field and understand how this technology can be best understood and adopted by the local communities.

Project lead and Lecturer in the Department of Chemical Engineering, Dr Emma Emanuelsson, said: “The potential to develop a cheap, durable and portable device which can provide those most in need with safe, clean drinking water is an exciting prospect.

“The key strength of this project is its simplicity and the multi-disciplinary approach taken. Our skills and expertise complement each other, combining maths with engineering with social sciences will ensure we develop an effective water treatment device that is both useful and accepted in rural African communities.”

Multi-disciplinary approach

The team at Bath will benefit from the skills and expertise of a wide range of academic disciplines.

Mathematicians in the Bath Institute for Mathematical Innovation (BIMI) will develop a mathematical model to calculate the time it takes water to travel through the device prototypes; digital design experts in Civil Engineering will develop cutting edge software for designing different treatment device prototypes which can then be easily exported to a 3D printer for fabrication; Chemical Engineers will evaluate the effects of different conditions such as temperature, light intensity and water turbidity; and experts in Social and Policy Sciences will help understand how these devices can best be adopted and used by local communities in rural areas.

This project is in receipt of funding from the Engineering and Physical Sciences Research Council (EPSRC) Global Challenges Research Fund (GCRF).

The researchers recognise the importance of ensuring this technology is successfully adopted by the African communities and are currently seeking funding to take forwards this technology and work with local NGOs such as CCODE (Centre for Community Organisation and Development) to ensure that the water-treatment prototype becomes a community-led innovation.